json_dump: draft of reconnect feature

[cejkato2]

No description provided.

[hejcman]

Code review comments:

• Avoid using optparse, it is deprecated since Python 3.2. Use argparse instead.
• It is unnecessary to do manual checks for argument exclusivity, argparse has built in support for mutually exclusive groups.
• Prefer placing as much code as possible into functions. If the file is imported, any code writen in the main body of the file is executed, which could for example overwrite your global variables.
• Avoid unecessary commands such as del (e) when e goes out of scope anyway and pass.
• Remove unused imports.
• Where possible, write typehints for function or important variables.